`who killed the bird?` the passive form of the sentences is-
who was killed by the bird?
who was killed the bird?
By whom the bird was killed
By whom was the bird killed?
Explanation:
Correct Answer is: By whom the bird was killed

who was killed by the bird?
who was killed the bird?
By whom the bird was killed
By whom was the bird killed?
Correct Answer is: By whom the bird was killed

Mr. Qureshi is a university Professor. Here `university` is a- Option A: Noun , Option B: Determiner , Option C: Noun adjective, Option D: Pronominal adjective, correct answer is: Noun adjective
Go and catch the falling star. Here the “falling” is- Option A: an adverb , Option B: a preposition , Option C: an adjective, Option D: a verb, correct answer is: an adjective
Let the task ___ done as directed. Option A: is , Option B: to be , Option C: was, Option D: be, correct answer is: be
There has been a breakthrough in the treatment of dengue. Here `breakthrough` is a/an: Option A: adjective , Option B: verb , Option C: noun, Option D: adverb, correct answer is: noun
I prefer tea - milk. Option A: than , Option B: then , Option C: to, Option D: more, correct answer is: to